Improvement in elevators



- UNITED STATES lPATENT OFFICE.

CHARLES WHITTIER, OF BOSTON, MASSACHUSETTS.

n wPRovEMENT IN EELEvAToRsK.

Specification forming part of Letters Patent o. 154,108,11ated August 11, 1874; applic'ation med June I9, 1874. i

To all whom it may concern:

Baitlknown that I, CHARLES WHITTIER, of Boston, in the county of Sui'olk and State of Massachusetts, have invented an Improvement in Elevators or Hoisting-Machines; and I dohereby'declare that the following, taken 1n connection with the drawings which accompany; and form part of this specification, is a description of my invention sufficient to enable those skilled in the art to practice it.

The invention has reference to a provision, 1n connection with the winding-drum of an elevator, for stopping the driving shaft, and therebyzarresting the windingdrum whenever,for any reason, the hoisting-rope slacks.

In 'many elevators an automatic stop-ma tion 1s applied for arresting the driving-shaft, byshifting the belt fromthe fast" to a loose pulley, orby shutting off steam if a hoistingengine be used, when the car reaches the upper or lower floor; and in my invention I cornblne, with the gearing of such automaticzstopmotlon and theslide-bar that shifts the belt orvalve, a mechanism that is engaged with the gear of the shifting-bar, to operate the bar by the slack of the rope.

.My invention consists,primarily, in the combmatxon, with a stopmotion operated by a gear-nut riding on thelscrew-threaded shaft, of the winding-drum, or a screw-threaded shaft operated thereby, and a mechanism operated by a slacking'rope to engage with the mechanism of the shifting-bar, and operate said bar.

The drawing represents a winding drum :ttndldrum mechanism embodying my inven- 2 is'an end view of it. the line x.

a denotes the winding-drum; b, the drumshaft; c, the 'worm-gear of said shaft; d, the worm that drives the same, said worm being on the driving-shaft e, and said driving-shaft carrying the fast and loose pulleys, or being connected with the shaft of the engine, if a hoisting-engine be: used. f denotes the belt or valve shifting bar, jointed to an arm, g, of the shifting-shaft h. On the shaft his fixed the gear-pinion 13, that engages with the gear- Fig. 3 is a section on nutk on the drum-shaft b, said shaft being screw-threaded, and the gear-nut k. being driven endwise as the shaft rotates. Its endwise motion is between a gear or collar, l, fast onrthe drum-shaft, and made adjustable by `means of a key entering a groove in the collar 'and in the shaft, and a collar, m, also fast upon said shaft, this latter collar being made adjustable on the shaft, as hereinafter described,

and being set in accordance with the extent of vertical movement the car is to have in each direction, each collar having a clutch on itsy vinner face to engage with a clutch on the adjacent face of the sliding gear k, and this gear being always in engagement with the gear-pinion t' on the shifting-shaft h, the clutching of the gear-nut k with the collar on either side of it causing the shifting-shaft to be operated to shift the belt from the fast to the loose pulley, or to shut off steam.

' The mechanism thus described composes the ordinary stop-motion; and with this motion is connected the slack-rope stopl-motion as follows: On the shifting-shaft h is a slide-pinion, n, having anannular groove, o, into which enterslafork), extending fromashaft, q. On the outer end of this shaft is an arm, r, that normally rests on a shoulder, s. of a lever, t, said lever being hinged "at u, andhaving its inner end extending under the hoisting-drum, with a bar, c, projecting laterally in each direction from it, so that, if any coil of the rope on the drum slacks in the'least degree from the drum it will strike the bar c, and tip the lever t, so

as to dislodge the army fr from the shoulder s,

the arm being then free to fall by gravity, Flgure 1 shows the mechanism in plan. Fig.`

The arm, in falling, throws the pinion n toward thepinion t', the two pinions being pr0- vided with clutches or clutch-pins w w, and their contact being insured by the dropping ofthe armr, the contact causing the move ment of the valve or belt-shifting bar f.

By this arrangement the two stop-m0- tions are combined; but it will be obvious that the mechanism operated by the slack of the hoisting-ropemaybe used independently from the c1utch-collars lm and gear-nut k.

The collar' m is shown as made with two flanges, y z, the flangey being made fast to the shifting mechanism, substantially as Y described. 'y Y 2. In combination with the stop-motion, op`

erated bythe Ydrum-shaft, a stop-motion op# erated by the hoisting rope, substantially as described.

3. The lever t, arm 7', shaft q, fork p, and clutch-Wheels l m, arranged and combined to operate substantially as described.

4. The clutch-collar m, formed with two relatively-adjustableflanges, y z, substantially as shown and described.

CHARLES WHITTIER.

Witnesses M.- W. FROTHINGHAM, S. B. RIDDER. 

